Reinforced concrete guardrails for use along roadways are prefabricated at one location and shipped to another location for installation. In particular, such guardrails are massed produced in straight sections at a manufacturing site. The straight sections are then transported to roadway where a barrier is required. The sections are then placed end to end along a roadway and secured to each other to form a continuous barrier.
At various times during this process of manufacturing and installing the individual sections it is necessary to manipulate and otherwise move these sections. Forklifts are often used to move the sections around at both the manufacturing site and the installation site. While forklifts are able to accomplish this task, often the bottom edges of the guardrail sections are damaged by the tines of the forklift as the operator attempts to insert the tines underneath the sections. Heretofore, this has been considered acceptable even though such damage detracts from the appearance of the finished barrier because the barrier serves its basic purpose. Further, it is possible to patch the barrier section to repair such damage. However, it would be desirable to eliminate the possibility of this damage.
Additionally, often it is necessary to rotate or otherwise manipulate the individual sections subsequent to the casting process. A relatively advanced apparatus for manipulating these sections during casting is depicted in FIGS. 1 and 2.
Shown in FIG. 1 is a rotating apparatus 20 for rotating a form 22 to facilitate removal of a concrete guardrail section 24 (FIG. 2E) therefrom. The rotating apparatus 20 comprises a main structural member 26, first and second rollers 28 and 30, first and second roller belts 32 and 34, a drive motor 36, a roller shaft 38. The rollers 28 and 30 are connected to the roller shaft 38, which is mounted to the structural member 26 by bearings 40, 42, 44, and 46. The drive motor 36 is mounted to the structural member 26 by a mounting frame 48. A drive shaft 50 of the motor 36 is connected to the roller shaft 38 by a chain 52 such that operation of the motor 36 axially rotates the roller shaft 38. The roller belts 32 and 34 are looped around the rollers 28 and 30. Hooks 54 and 56 extend from the bottom of the structural member 26.
The rotating apparatus 20 operates basically as follows. Tines 58 of a forklift 60 are placed under the structural member 26 (FIG. 2A). The roller straps 32 and 34 are placed underneath the form 22 as shown in FIGS. 1 and 2A. The form 22 is then lifted by raising the tines 58 (FIG. 2B). The motor 36 is then operated to rotate the straps 32 and 34 in the directions shown by arrows A and B in FIG. 2B. The straps 32 and 34 frictionally engage the form 22 such that rotation of the straps 32 and 34 also causes the form 22 to rotate 180.degree. about its lengthwise axis 62 (FIG. 1) into the position shown in FIG. 2C. The tines 58 are then lowered until the form 22 again rests on dunnage 64 (FIG. 2D). The straps are then removed, and the hooks 54 and 56 inserted into loops 66 and 68 on the form 22. The form 22 is then moved in the direction shown by arrow C in FIG. 2D to lift the form 22 off of the guardrail section 24 as shown in FIG. 2E. The forklift 60 may then be employed to move the section 24 as discussed above.
The apparatus 20 is fairly labor intensive because two persons are required to remove the barrier section from the form (one to operate the forklift, the other to manipulate the roller belts) and only one barrier section can be removed at a time. The exemplary apparatus 20 described above requires approximately six man-minutes to remove one barrier section from a form.
While the rotating apparatus 20 discussed above significantly automates the process of removing guardrails sections from their forms, this apparatus 20 is limited in that it: (a) handles only one form at a time; (b) damages the form in the process; and (c) does not address the problems discussed above with current methods of moving guardrail sections around once they have been removed from the form.
Accordingly, it is an objective of the present invention to overcome the above-identified problems by providing improved methods and apparatus for manipulating concrete barrier sections.